Blast radius

The maximum or expected extent of people, data, money, systems, geography, or time affected by one failure or compromised action.

Radius includes more than item count. One changed authorization rule may affect every future request, while a single leaked medical record may be severe despite touching one person. Reversibility, detectability, propagation speed, sensitivity, and dependency reach help characterize the effect.

Builder example

Containment can use batch limits, canaries, account and tenant boundaries, destination allowlists, rate limits, transactions, backups, staged rollout, and authorization gates where judgment or ownership requires them. A small-radius operation can often run automatically when monitoring and recovery are strong.

Common confusion: Blast radius is one risk dimension. Probability, severity, exposure, detection time, reversibility, and control strength still affect the route; high radius does not automatically imply one universal manual gate.